Main · scanningChoose your sails
Scan the tag in the tack or pick your sailmaker. We load the sail's design targets so every scan is judged against how it was built to look.
- Design camber targets from Doyle, 6 to 22 kts
- Accepted range ±2 points at every wind speed
- Trim advice for outhaul, cunningham, vang and backstay
Tag matched · ready to scan
Demo for Doyle Sails - all numbers illustrative.
Input wind speed
What was the wind speed when the photo was taken? We’ll use that to determine Doyle's ideal shape for your sail
Demo: the rest of the flow is fixed at 14 kts.
Great scan. Your main is a little full in the lower stripe (40%), 16.9% deep where this cruising main wants about 13% in 14 knots. Your top, upper and bottom stripes are clearly in the acceptable range, so the sail is mostly right where it should be.
To point higher and carry less heel, flatten the lower half of the main. Pull on more outhaul, then ease the traveler down a touch so the foot flattens without closing the upper leech. If it still looks deep, add a few turns of backstay to bend the mast and pull the draft out of the belly. Leave the halyard alone; the draft is already where it should be.
You should see a boat that points higher, carries less heel and stays on its feet in the puffs, with the same durable Dacron doing the work. Go!
Lower stripe fuller than target. Top, upper and bottom in range.
| Stripe | Camber % | Draft % |
|---|---|---|
| ■ 80% Top | 14.6 | 35.0 |
| ■ 60% Upper | 13.4 | 36.0 |
| ■ 40% Lower | 16.9 | 38.0 |
| ■ 20% Bottom | 12.1 | 34.0 |
The airflow is a fast flow model worked out on this phone for these exact shapes. It shows attached flow only, not stall, so use it to compare trim, not instead of telltales. Colours are relative.
| Stripe | Target | Accepted | Measured | Verdict |
|---|---|---|---|---|
| Top | 13.0% | 11 to 15% | 14.6% | in |
| Upper | 13.0% | 11 to 15% | 13.4% | in |
| Lower | 13.0% | 11 to 15% | 16.9% | high |
| Bottom | 13.0% | 11 to 15% | 12.1% | in |
Targets from your Doyle Dacron Cruising Main design at 14 kts. Assumes a cross-cut Dacron main with outhaul, cunningham and an adjustable backstay.
Demo for Doyle Sails - all numbers illustrative. One made-up scan (4 stripes, 14 kts) is used on every screen; the target curve is a generic 16% to 10% rule.